I have found and bought some pouch cells. They are EIG C020 cells: each with 20Ah with a nominal voltage of 3.6V. I chose them for several reasons: 1. Pouch cells have a higher C rating than tube cells (mine can discharge at 5C continuous (i.e. 100A in my configuration) and up to 10C for 10 seconds, meaning you can get higher discharge rates without requiring a high capacity. 2. Mounting is easier because of their design: busbars can be bolted and they can be bolted together. This removes the need to spot weld (and, therefore, the need for a spot-welder). 3. The larger capacity means fewer cells are needed, as each has a relatively high Ah capacity. These batteries will run in a 1P14S configuration to get to 20Ah and 52V; rather than, say, 195 cells needed for a 15P14S battery of the same specs.
